Process and composition for the electrodeposition of tin and tin alloys
AssigneeOccidental Chemical Corporation
InventorsRobert J. Teichmann, Linda J. Mayer
Life of this patent
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Abstract
An electroplating bath for the high speed deposition of bright metallic tin utilizing tin fluoroborate and sulfuric acid as the electrolyte; wherein, in addition to certain other additives, the bath contains a perfluoroalkyl sulfonate wetting agent to promote anode corrosion. Brighteners used in the system include aromatic amines and aliphatic aldehydes. For certain purposes it may be advantageous to include boric acid as part of the electrolyte; and, in other instances, to use an aromatic sulfonic acid to enhance bath stability and brightness. The method for utilizing a bath containing tin fluoroborate in a sulfuric acid matrix containing these perfluoroalkyl sulfonate wetting agents is also described.
Claims14
An aqueous electroplating bath for the electrodeposition of bright, metallic tin or alloys of tin with copper or rhodium which comprises from 5 to 50 g/l of a bath soluble di-valent tin compound, sulfuric acid in an amount sufficient to maintain the bath pH not in excess of about 2.0, 0.01 to 10 g/l of a perfluoroalkyl sulfonate wetting agent, 0.3 to 15 cc/l of an aromatic amine brightener, 0.1 to 20 g/l of a non-ionic surfactant, and 0.5 to 30 g/l of an aromatic sulfonic acid, said bath being substantially free of other sulfur components.
Dependencies are inferred from the claim text.